Vapor-electric devices



Aug. 30, 1955 LA|D|G 2,716,715

VAPOR-ELECTRIC DEVICES Filed May 28, 1952 lNVENTOR /4 H. LH/DICF.

gg BY ATTORNEY United States Patent VAPOR-ELECTRIC DEVICES Alfred H.Laidig, Essex County, N. 1., assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication May 28, 1952, Serial No. 290,587 7 Claims. (Cl. 313-328)This invention relates to vapor-electric devices such as are generallyknown as ignitrons.

There are in the art several examples of ignitrons utilizing semi-solidor sponge cathodes, and the present invention contemplates improvementthereover.

Approached in its broader aspects, an objective of the present inventionis to obtain a more stable and unfailing arc discharge in an ignitron.

A further object of the invention is to provide for a more effectivecycle of vaporization of the liquid cathode material at the region ofarc instigation.

More specifically, the invention provides for a copious supply of theliquid cathode material at that region of the sponge cathode body at thepoint of arc instigation by the ignitor.

Another object of the invention is to provide for the rapid absorptionof condensed cathode material and provision of a reservoir for receptionthereof, in combination with means for returning the liquid cathodematerial to the region of arc instigation.

Other objects of the invention will appear to persons skilled in the artto which it appertains as the description proceeds, both by directreference thereto and by implication from the context.

Referring to the accompanying drawing in which like numerals ofreference indicate similar parts throughout the several views;

Figure 1 is a vertical section of an essential portion of an ignitronwherein the present invention is included in one form thereof;

Figure 2 is a cross-section on line II-II of Fig. l; and

Figure 3 is a vertical section similar to Fig. l and showing a modifiedform of cathode body and of the invention adapted thereto.

In the specific embodiment of the invention and associated ignitronconstruction illustrated in the drawing,

but without limiting to details thereof, a sealed cylindrical casing ofsteel or other sturdy material is shown having a bottom 12 integraltherewith and having, at a distance above said bottom, an anode 13appropriately supported and insulated from the casing as usual in theart. Between said anode 13 and bottom 12 is an ignitor 14 here shownlocated axially of the container and directed toward and terminating atits bottom in engagement with a sponge cathode body 15 locatedsubstantially on the bottom wall 12. Said ignitor may be composed ofmaterials, such as boron, boron carbide and boron nitride as used forignitors of the prior art, or may be of such other material or materialsadapting it more especially to the present invention.

Said sponge cathode body 15 preferably fits the con tainer at itsperiphery and may be suitably held in place, as by means of a pluralityof indentations 16 made in the wall of the container, as shown inFigures 1 and 2 such that the indentations project into the periphery ofthe cathode body. Alternatively, retention of the cathode body 15a, asshown in Fig. 3, may be accomplished by a stud 16a projecting from thebottom wall 12a into the lit) 2,716,715 Patented Aug. 3Q, 1955 of thecontainer at its periphery, but also provides a bottom rim 19 next theperiphery to rest ,upon the said bottom wall of the container andthereby form and maintain the hollow 17 at the underside of said bodywith the bottom of the container utilized as the bottom of thereservoir.

It is furthermore desirable to bevel the upper peripheral corner of thecathode body, and thereby .provide a peripheral trough 20 next the sidewall of the container, between it and the surface of the cathode body toreceive condensed mercury or the like which gravitates down the saidside wall. The mercury then passes through the sponge body intoreservoir 17. To aidthe mercury and obtain faster draining of thetrough, a plurality of capillary passages 21 are provided in the cathodebody from proximity to the beveled edge surface thereof to the saidreservoir. The said passages preferably slope downward toward thereservoir so as to take advantage of gravity in addition to capillarityfor aiding in the flow of the mercury.

At the midsection of the cathode body there is shown a downwardlyextending boss or hub 22 the under face of which is in proximity to butdefinitely spaced from the bottom wall 12 of the container. In effect,therefore, this boss or hub is submerged in-the mercury or the likecontained in the reservoir. This boss or hub is provided with aplurality of capillary passages 23 which are open at the under face ofthe hub and extend approximately to the surface of the cathode body inproximity to the location of the ignitor. There is, however, a thinclosure of the sponge material of the cathode at the upper ends of thecapillary passages through which the mercury may seep in use. Theproximity of the upper ends of the capillary passages is conducive to acopious flow of mercury to the upper surface of the cathode. The factthat the lower ends of the capillary passages are always submerged inthe mercury pool in the reservoir assures a constant supply to the uppersurface of the cathode.

It is within the scope of the invention to use any desired fabricationof cathode body. In Fig. l the body is shown as in most part of onesponge material and having a central disc or insert 24 at its uppersurface for are striking purposes. By way of example, the major part ofthe cathode body may be a sponge of sintered iron, whereas therestricted are striking insert 24 may be of some more refractory spongematerial such as sintered ruthenium, molybdenum or the like. With acompound body of this character, the capillary passages may extendupward to the under portion of the insert and thus feed mercury directlythereto and in addition to the mercury which is fed through the pores orinterstices of the sponge.

Where, as shown in Fig. 3, a cathode body of one sponge material isemployed, that is, without an insert, the capillary passages 23preferably stop short of the upper surface so the mercury has to feedthrough a closure layer of the sponge material. This not only givesdesired distribution of the mercury on the surface, as well as arestriction in droplet size, but avoids spurts of mercury which mightoccur if the passages were open at their upper ends. The sponge body maybe sintered iron alone or in combination with some other material mixedtherewith, such as a mixture of iron and molybdenum, or may be sinteredmolybdenum or other material or combination of materials.

I claim:

1. A sponge cathode comprising a body portion of a sponge materialhaving a reservoir next one face thereof, and having capillary passagesopen to said reservoir and extending therefrom in said body portion.

2. A sponge cathode comprising a body portion of sponge material havinga reservoir and a trough separated by an intervening thickness of saidsponge material, said intervening thickness of the sponge materialhaving capillary passages part way through the same.

3. A sponge cathode comprising a body portion of sponge material havinga reservoir and a hub dipping into said reservoir, and said hub havingcapillary passages extending in a direction from the reservoir to anupper part of the body portion.

4. An ignitron comprising a side wall and a bottom wall, a spongecathode extending to engagement with both of said walls, said cathodeproviding a reservoir between a portion thereof and the bottom wall andproviding a trough between a portion wall.

5. An ignitron comprising a side wall and a bottom wall, a spongecathode extending to engagement with both of said Walls, said cathodeproviding a reservoir between a portion thereof and the bottom wall andproviding a trough between a portion thereof and the side thereof andthe side a wall, and said cathode having capillary passages thereinsubstantially from said trough to said reservoir.

6. An ignitron comprising a side wall and a bottom wall, a spongecathode extending to engagement with both of said walls, said cathodeproviding a reservoir between a portion thereof and the bottom Wall andproviding a trough between a portion thereof and the side wall, and saidcathode having a hub depending into said reservoir.

7. An ignitron comprising a side wall and a bottom wall, a spongecathode extending to engagement with both of said walls, said cathodeproviding a reservoir between a portion thereof and the bottom wall andproviding a trough between a portion thereof and the side wall, saidcathode having a hub depending into said reservoir, and said cathodehaving capillary passages opening into said reservoir with some of saidpassages in said hub and others extending substantially to said trough.

References Cited in the file of this patent UNITED STATES PATENTS

